1. Field of the Invention
This invention relates generally to lawn maintenance equipment and more particularly to a wheel set for a lawn comb or thatcher.
2. Description of the Prior Art
Early each spring home owners and lawn maintenance workers begin to clear lawns of the debris collected over the winter. Along with this the lawns are generally seeded and fertilized as soon as the ground is stable enough to accept the weight of the equipment used in the process. Due to natural environmental conditions some soils are difficult to stabilize. Wind and sun will dry good draining soil quickly, while cloudy damp weather and poor soil and drainage will delay work schedules.
A piece of equipment used in both the clearing and pre-seeding process is the lawn comb also called the lawn thatcher. The lawn comb consists of a power driven shaft containing a quantity of spring mounted tines that are contained in a housing mounted on adjustable wheels. The housing is rolled across the lawn and the tines loosen prior seasons thatch and leave a small mark of disturbed soil. In the case of a new lawn there would be no thatch and the tines would simply score the soil and make it particularly receptive to the application of grass seed.
The depth of the score mark is important to the successful growth of the seed and depth is regulated by adjustment of the wheels attached to the housing. Under early spring conditions adjustment becomes a problem in that because of the power unit the thatcher is relatively heavy and settles into the soil and varies the adjustment as it travels across the lawn which in turn will vary the growth pattern of the grass.
One solution to the problem is to distribute the weight of the equipment over a larger area by increasing the size of the wheels. Existing equipment, however, is not readily adaptable to simply adding wide wheels. The wheels on equipment currently available are in close proximity to the housing and drive mechanism and do not readily lend themselves to substitution.
U.S. Patents of interest include U.S. Pat. No. 2,715,882 issued Aug. 23, 1955 to Overstreet,Jr. for a grass planting machine with variable depth control. U.S. Pat. Nos. 4,126,190 issued Nov. 21, 1978 to Wylie; 4,553,607 issued Nov. 19, 1985 to Behn et al.; 4,702,323 issued Oct. 27, 1987 to Smit et al., and 4,974,683 issued Dec. 4, 1990 to Hanig et al all disclose tillage attachments to be drawn behind farm tractors but having wheels, linkage systems and adjustability. None of these references it believed to anticipate this invention.